1. Field of the Invention
The present invention relates to a method for operating a safety device for a handling device. Furthermore, the present invention relates to a safety device for a handling device and a handling device.
2. Description of the Related Art
A method of this type for operating a safety device for a handling device is already known from published German patent application document DE 10 2007 062 245 A1. Here, the safety device has a shell surrounding the handling device in the form of a fillable medium storage device, which is in operative connection with a pressure sensor. When a collision is recognized, the pressure sensor responds, whereupon the gripper arm is stopped or moved in an opposite direction. Since the safety device does not respond until contact or collision with an object, for example, an inanimate object or a person, has already occurred, the necessary change in motion or stopping must occur in an extremely short period of time in order to prevent damage or injury. Therefore, when a collision of this type is recognized, an “emergency stop” of the handling device or of the gripper arm is usually performed. An “emergency stop” of this type has, however, the disadvantage that the motion velocity is not reduced to the value zero in a controlled manner. After the collision risk has been eliminated, the gripper arm must be brought back into a certain position, for example, from which a predetermined motion sequence is possible or the control program must be resynchronized with the gripper arm motion.
Furthermore, it is known from published European patent application document EP 1 323 503 A2 to provide a multistage sensor system in order to make possible a risk-free operation of the handling device involving human interaction. The method is based on tactile function principles, although a capacitive sensor principle is described as a possible sensor principle. The capacitive sensor principle, however, has only a supplementary function, i.e., it is usable only together with additional safety mechanisms such as a foam padding or a tactile sensor system. A targeted, collision-free braking action is thus not provided. In the last-named safety device, a foam padding shell surrounding the handling device is, in particular, also used for dampening or absorbing the impact energy generated in the collision.